﻿Directive 
  System 
  of 
  Wireless 
  Telegraphy 
  . 
  

  

  653 
  

  

  detector 
  into 
  phase 
  by 
  any 
  means, 
  the 
  effects 
  of 
  the 
  two 
  will 
  

   be 
  added. 
  When 
  the 
  transmitting 
  station 
  finds 
  itself, 
  

   similarly, 
  in 
  the 
  plane 
  of 
  the 
  closed 
  circuit 
  but 
  on 
  the 
  south 
  

   side, 
  the 
  effects 
  of 
  the 
  two 
  systems 
  counteract 
  one 
  another. 
  

   If 
  the 
  directive 
  aerial 
  of 
  the 
  receiving 
  station 
  is 
  composed 
  

   of 
  two 
  closed 
  oscillatory 
  circuits 
  connected 
  to 
  the 
  receiving- 
  

   radiogoniometer, 
  the 
  phase 
  of 
  the 
  E.M.F. 
  induced 
  in 
  the 
  

   movable 
  winding 
  of 
  the 
  apparatus 
  will 
  vary 
  by 
  180° 
  when 
  

   the 
  coil 
  is 
  turned 
  through 
  180°. 
  So 
  that 
  the 
  action 
  of 
  the 
  

   directive 
  aerial 
  in 
  one 
  case 
  will 
  add 
  itself 
  to 
  that 
  of 
  the 
  

   vertical 
  antenna, 
  and 
  in 
  the 
  other 
  case 
  will 
  subtract 
  itself 
  

   therefrom. 
  It 
  follows 
  that, 
  to 
  the 
  position 
  of 
  maximum 
  

   reception 
  of 
  the 
  movable 
  coil, 
  there 
  corresponds 
  a 
  position 
  

   of 
  zero 
  or 
  minimum 
  reception 
  when 
  the 
  coil 
  is 
  turned 
  through 
  

   180°, 
  which 
  thus 
  permits 
  of 
  the 
  determination 
  not 
  merely 
  of 
  

   the 
  direction 
  of 
  the 
  transmitting 
  station, 
  but 
  also 
  of 
  the 
  side 
  

   which 
  it 
  is 
  on. 
  

  

  The 
  action 
  of 
  the 
  detector 
  depends, 
  as 
  in 
  the 
  case 
  of 
  the 
  

   transmission, 
  upon 
  the 
  values 
  of 
  the 
  phase-difference 
  between 
  

   the 
  actions 
  of 
  the 
  two 
  systems 
  and 
  on 
  the 
  ratio 
  M/C. 
  The 
  

   law 
  of 
  variation 
  of 
  this 
  action 
  is 
  the 
  same 
  as 
  that 
  of 
  the 
  

   variation 
  of 
  the 
  resultant 
  electromagnetic 
  field 
  at 
  the 
  trans- 
  

   mitter 
  and 
  the 
  diagrams 
  are 
  the 
  same. 
  

  

  Fio-. 
  13. 
  

  

  Fiff. 
  14. 
  

  

  To 
  obtain 
  quadrature 
  between 
  the 
  actions 
  of 
  the 
  vertical 
  

   antenna 
  system 
  and 
  that 
  of 
  the 
  directive 
  bilateral 
  system 
  

   several 
  arrangements 
  have 
  been 
  tried 
  which 
  are 
  shown 
  in 
  

  

  figs. 
  13, 
  II, 
  lo. 
  

  

  